UEFN Crashing when editing terrain to fast

Explanation:
well after i edit the terrain fast on my pc the editor just crashes with following error code:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff

Evidence:
screenshot and logfile

If replicable, how:
edit the terrain fast

Platform:
PC
UECC-Windows-874CF3FB4770C331836C7AA0317C7C7A_0000.zip (243.1 KB)